Centrifugal pump and motor

ABSTRACT

A centrifugal pump and motor, which may be submersible, comprising an impeller and housing means therefore including an axial diffuser, a motor in axial alignment with the impeller, and a common shaft for the motor rotor and the impeller. A tubular means encompass the motor for its length and connects to the axial diffuser for flow of pumped liquid therethrough for cooling the motor, while outlet means connect to the tubular means and an end of the shaft is journalled on a portion of the outlet means. Additionally the invention includes a vortex separator provided to receive some of the outlet liquid and means connect the cleansed outlet liquid form the vortex separator for flow of such liquid to a seal provided at the pump for seal flushing action, which seal flushing liquid can also be used to flush out the clearance spaces in the pumping chamber.

United States Patent 1191 Kaessen Nov. 26, 1974 [54] CENTRXFUGAL PUMP AND MOTOR 3,736,075 5/1973 Otto 417/424 [75] Inventor: Donald A. Kaessen, Ashland, Ohio Primary Examiner-C. J. Husar [73] Asslgnee: Q' P Company Attorney, Agent, or Firm-Oldham & Oldham Co.

Hayesvllle, Oh1o [2|] Appl' 169353 A centrifugal pump and motor, which may be submersible, comprising an impeller and housing means [52] US Cl 417/372, 415/109, 415/111, therefore including an axial diffuser, a motor in axial 417/424 alignment with the impeller, and a common shaft for 1511 Int. Cl. F04b 17/00 the mot r r t r and th impell r- A tubular means n- 1581 Field of Search 417/372, 424; 415/109, omp the m t r for i length and connects to the 415/ 1 10, 111 axial diffuser for flow of pumped liquid therethrough for cooling the motor, while outlet means connect to [56] R fere Cit d the tubular means and an end of the shaft is journalled.

UNITED STATES PATENTS on a portion of the outlet means. Additionally the in- 506 827 5/1950 Goddner 417 42 4 vention includes a vorte t separator provided to re- 2:885:963 5/1959 1vanofr...:. :::IZIIIIIIIII: 417/424 some of the Outlet quld and means connect the 2,963,980 l2/1960 White 415 110 cleansed Outlet liquid m "Ortex separato for 3,186,5l3 6/1965 Dunn et a]. 415/110 flow of such liquid to a Seal lmwided-at the P p for 3,494,291 2/1970 Carter, Jr 417/424 al flushing action, which seal flushing liquid can also 3,644,067 2/1972 Yowell 417/372 be used to flush out the clearance spaces in the pump- 3,652,l86 3/l972 Carter 4l5/l l0 ing chamber. 3,694,110 9/1972 Guinard.... 417/424 3,698,830 l0/l972 Go ne 4l5/l ll 10 Claims, 3 Drawing Figures CENTRIFUGAL PUMP AND MOTOR The present invention relates to centrifugal pump and motor units, and particularly to a unit which is adapted to be operated in any desired position and which unit will handle, safely, pumped-liquids having abrasive liquids therein, or hot boiling water containing sand or abrasive materials or other hot, caustic corrosive water solutions, such as atomic waste water.

BACKGROUND OF THE INVENTION Heretofore there have been many different types of pumps provided for a wide variety of purposes. While some of these pumps have been designed for use with abrasive materials, or liquids containing abrasive materials, or have been designed for use with hot water, or caustic, still it has been difficult to obtain any satisfactory pump life in many instances. The abrasive material tends to wear out the seal or packing means in the pumps rapidly, or the pump motor may become overheated easily, the pumping assembly may be limited in the positions in which it can be used, or the caustic materials may damage the sealing means for the pump.

The general object of the present invention is to provide a novel and improved centrifugal pump and motor assembly which is adapted for pumping liquids with abrasives therein and which is characterized by the improved wear and service life of the assembly.

Another object of the invention is to provide a pump forpumping liquids with abrasives therein with a self contained vortex separator and to transfer the clean liquid output from such separator to seal means in the pump for seal flushing action. 7

Another object of the invention is to provide a compact, sturdy pump and motor unit wherein a portion of the outlet means provided in the pump will aid in positioning a common shaft for the motor and pump in the pump and motor unit.

Another object of the invention is to provide a pump for abrasive and caustic materials with improved service life and with improved seal and pump chamber flushing means.

Another object of the invention is to provide a tubular means connecting to the pump outlet and have such tubular means encompass the motor in the pump and motor unit for cooling the motor by flow of the pumped liquid therearound and to provide improved seal and cooling means in a pump and motor assembly.

Yet another object of the invention is to provide a pump and motor unit which can be submersed in the pumped material, if desired, and be supported in any desired manner and to provide-a suitable sealed electrical connection to the motor and to provide cooling liquid forcibly pumped around in the motor for cooling the motor and varying means for the motor shaft.

The foregoing and other objects and advantages of the invention will be made more apparent as the specification proceeds.

Reference now is made to the accompanying drawings wherein:

FIG. I comprises a longitudinal section of the pump and motor unit of the invention;

FIG. '2 is an end elevation of the upper end of the unit of FIG. 1 with the end cap removed therefrom; and

FIG. 3 is an enlarged view of a portion of the pump and the flushing means for the pump.

sponding numerals are used to facilitate comparison therebetween,

INVENTIVE SUBJECT MATTER A centrifugal pump and motor comprising, as an embodiment of the invention, an impeller and housing means therefor including an axial diffuser, a motor in axial alignment with the impeller, a common shaft for the motor rotor and the impeller, tubular means encompassing the motor for the length thereof and connecting to the axial diffuser for flow of pumped liquid therethrough for cooling the motor, an outlet means connecting to the tubularmeans, means on the outlet means journalling an end to the shaft thereon, a vortex separator connected to the outlet means to receive a part of the pumped material or liquid therefrom, a seal means being provided for the shaft adjacent the impeller, and means connecting the clear liquid output of the vortex separator to the seal means for flushing .the

same.

With reference to the details of the structures shown in the drawings, a pump and motor of the invention is indicated as a wholeby the numeral 10. This unit 10 includes a pump generally designated by the numeral 12, a sealed chamber 14 positioned adjacent the discharge side of thepump 12, a 3-phase electric motor 16 and a housing which is indicated as a whole by the numeral 18.

At the inlet end of the pump and motor unit, a suitable strainer means or member 20 is provided and it is secured to an end plate or portion 22 of the housing 18 by cap screws-or bolts 24, or similar means. The end plate 22 forms a portion of the housing for the pump 12 and the other side or portion ofa housing for enclosing the pump 12 includes a backing plate 26. A diffuser ring, or axial flow diffuser member 28 provides a peripheral enclosure for the pump 12 and this axial flow diffuser 28 includes an arcuately curved section or face 30 that aids in turning the output from the pump 12 from flowing in a radial direction to flow in an axial direction as indicated by the arrows 31 on the drawings.

The pump 12 has an inlet indicated at 32 which is formed in the end plate 22 and a centrifugal flow impeller 34 is rotatably positioned in a pumping chamber defined by and formed between the end plate 22, backing plate 26 and diffuser 28. The impeller 34 includes a face shroud plate 36 and a rear impeller shroud or wall 38 with any suitable impeller blades 39 being provided between the shrouds 36 and 38of the impeller and forcing pumped liquids'centrifugally outwardly of the pump 12.

The impeller 34 is secured to one end of a drive shaft 40 as by a cap screw 42 and a lock ring 44. Also, the impeller is secured to the shaftby a key 46.

As one feature of the invention, a tubular axial flow chamber 50 is formed within the housing 18 for receiving the discharge from the pump 12 and this extends axially of the pump and motor unit 10 to a position a'xially beyond the periphery of the motor 16 as hereinafter described in more detail.

SEAL CHAMBER The seal chamber 14 is formed within a substantially cupshaped member 52 the open end of which is attached to the backing plate 26 of the pump as by a cap screw means 54 or equivalent to form a chamber encompassing a length of the shaft 40. The backing plate 26 has an axial extension or bell 56 formed thereon, and suitable sealing means 58 of a conventional nature are received within this bell 56 at the end of it adjacent to the pump 12 and are retained in position by spring means compressed between the sealing means 58 and the adjacent end of the rear shroud of the impeller 34.

The opposite or second seal for the seal chamber 14 is provided by conventional means and include a packing means 60 engaging a shoulder on the inner surface of the base portion of the cup-shaped member 52 and which means are pressed into sealing relationship with each other around the shaft 40 as by a spring 62 confined against the packing assembly as by a retainer cup or cap located on the shaft 40 as by a locking washer 66 or the like.

The seal chamber 14 is normally filled to approximately 90 percent of its volume with a suitable seal lubricant such as a silicone oil or other conventional lubricant means whereby these seals are maintained in lubricated condition during use.

The motor 16 includes a rotor 70 that is suitably secured to a length of the shaft 40 and a stator 72 that is secured to and carried by the radially inner surface of a motor enclosure 74 received within the housing 18 and being in sealed engagement with the closed end of the cup-shaped member 52 as by a conventional O-ring 76 operativey positioned between the enclosure or sleeve 74 and an end portion of the member 52.

One support member for the shaft 40 comprises a conventional ball bearing 78 carried by a base portion of the member 52 and engaging and rotatably supporting the shaft 40. The bearing 78 is retained in position by an end ring 80 retained in position by cap screws 82 engaging the member 52.

HOUSlNG CONSTRUCTION The housing 18 also includes an outlet member 84 in which an outlet bore or opening 86 is provided and which connects to the axial flow chamber 50 formed by the enclosure sleeve 74 of the motor and the housing sleeve 88 by a connecting bore or chamber 90. The

outlet opening 86 in the end member provides axial discharge of the pumped liquid. Any suitable outlet pipe 92 suitably connects to the end member 84 for connection to conventional discharge means.

FURTHER FEATURES OF PUMP AND MOTOR As an additional feature of the pump and motor unit 10, a portion of the pumped outlet material flowing to the opening 86 will flow radially therefrom through a bore 94 that connects to a vortex separator means 96 carried by the end member 84. The end member 84 has a second strainer 98 affixed to or against a shoulder provided in an axially inner portion of the end member 84 whereby a further straining of the pumped material is provided before any portion thereof can flow to the vortex separator 96.

The vortex separator 96 has substantially tangential flow of liquid passing thereto as it flows into and around the closed end of this vortex separator 96 and with the material having a helical or spiral path to flow out through a discharge end 102 of the separator which end discharges into the end member 84 and flow therefrom around the outlet pipe 92 provided for the pump and flowing back into the sump or other chamber in which the unit 10 of the invention is positioned.

ln flow through the vortex separator 96, the already strained material has the solids therein carried therethrough with the primary flow of liquid material. However, a small portion of this liquid will take a reverse axial flow through the vortex outlet 104 provided by a tube 106 positioned in this separator. This outlet 104 connects to suitably axially extending holes bores or tubes 108 in the housing 18 and extending axially along the motor 16 to a connecting bore 110 formed in the cup-shaped member 52. The bore 110 in turn connects through a bore 111 in the bell 56 to a chamber 113 in which the seal means or packing means 58 is positioned to provide a packing or seal flushing action by such water supplied under pressure to the seal or packing means 58.

From this seal ring cavity or chamber 113, the clean liquid under pressure will flow through a bore 112 formed in the hub portion of the rear impeller shroud 38 of the pump and the clearance provided between a bushing 114 and the adjacent portion of the rear impeller shroud to the pump chamber. A wear plate or ring 116 is carried by the backing plate 26 but extends radially outwardly immediately adjacent the rear shroud of the impeller. The pumped seal flushing liquid or water will flow radially outwardly of the pump and flush out the clearance space provided between the backing plate 26 and the rear impeller shroud to discharge into the axial diffuser 28 with the other pumped liquid.

The invention also provides for flow of some of this clear pumped pressure liquid back axially through the impeller 34 by one or more bores 120 provided in the impeller so that the flushing liquid flows through the drilled passages or bores 120 to flush the front wear ring clearance provided between the end plate 22 and the axially forward or outermost portions of the impeller at the inlet of the pump. Part of the flusing liquid then will flow radially outwardly between the end plate 22 and the adjacent surface of the front shroud of the impeller and combine with the pumped liquid in the axial diffuser'and part of the flushing water will flow radially inwardly into the input liquid flowing into the pump 12. Hence, the pumped liquid, in substantially cleaned condition with no abrasive or grit therein, can be used for seal or packing flushing action and to avoid any abrasive material being confined in the pump. The flushing action obtained will aid materially in the service life of the pump produced.

Yet another feature of the invention is that the power supply for the motor as provided by lead will connect to suitable leads 132 coming from the stator of the motor and connecting to the power supply lead 130 at a connection means 134. This connection means may comprise any suitable receptacle where the leads 132 would be soldered or otherwise bonded to the power supply leads and then the entire material can be enclosed in a potting material, such as an epoxy material, for protecting these electrical connections from any possible contamination by the pumped material or liquid in which the unit of the invention is submerged.

The end member 84, or end bell of the motor is secured to the enclosure sleeve 74, as by removable pins or set screws 136 and a sealed connection is provided therebetween by means such as an O-ring 138 operatively positioned between adjacent surfaces'of these members and received in a recess provided in a peripheral portion of the end member 84.

Yet a further feature of the invention is that means are provided for circulating a lubricating and cooling material around in the motor 16. Thus, a suitable lubricating material such as silicone oil is indicated at 140 received within the sleeve enclosure 74 for the motor. This liquid can flow axially through the stator and openings therein and it then can flow through bores 142 provided in a support section 144 provided on the axially inner end of this end member. A conventional bearing 146 is carried by the support 144 and journals the end of the shaft 40 thereon. The lubricating material will flow through this bearing 146 and it also flows into an axially extending bore 148 provided in the shaft 40. The bore 148 extends the length of the motor 16 and usually a pair of axially spaced discharge bores 150 and 152 are formed in and extend radially of the shaft on opposite sides of the bearing 78 for flow of this insulating and lubricating fluid therethrough. Rotation of the; rotor will aid in circulating the insulating liquid around these bearings provided for the shaft 40 and aid in cooling the motor 16 at the same time.

An end cap or member 160 is suitably engaged with a peripheral portion of the end member 84 while a portion of the housing 18 also engages with this end mem ber 84 to form a continuous housing means enclosing the apparatus of the invention.

It will be seen that the pump and motor unit of the invention can be submerged in the pumped material and be supported therein in any desired way. The material discharged through or around the outlet pipe 92 will flow back out into the liquid in the sump in which the pump and motor unit is positioned. If an in line insulation is desired, the discharge from the vortex sepa rator and passing through the outlet 102 could be piped back to the pump inlet, or the separator could be omitted and seal flushing liquid could be separately supplied.

The flushing action provided for the packing means or seal assemblies in the invention, together with the flushing action around the pump impeller, reduces the wear on seals, wear rings and impeller shrouds and allows very satisfactory operational life for the pump and motor unit of the invention even when handling a high percentage of abrasive materials. The submersible unit of the invention is suitable for use in pumping boiling water containing abrasive materials, hot caustic, atomic waste water, etc. The axial flow diffuser 28 permits a small diameter unit to be provided. The lubricant and cooling systems can be used in a vertically or horizontally positioned unit, in a submerged or nonsubmerged pump, as desired. The impeller 34 is secured to the shaft at one end thereof and the lubricating liquid contacts both the motor stator and rotor and is circulated around in the motor and in its bearings by the liquid circulation means provided by the bores 142,

148, 150 and 152 in the shaft 40 by the rotation thereof. Hence, the objects of the invention have been achieved.

While one complete embodiment of the invention has been disclosed herein, it will be appreciated that modification of this particular embodiment of the invention may be resorted to without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

l. A centrifugal pump and motor comprising an impeller and housing means there for forming an impeller chamber adapted to pump water containing abrasive means, said housing means including a back wear ring,

an axial diffuser,

a motor in axial alignment with said impeller,

a common shaft for the motor rotor and the impeller,

tubular means encompassing said motor for the length thereof and connecting to said axial diffuser for flow of pumped liquid therethrough for cooling the motor,

an outlet means connecting to said tubular means,

means on said outlet means journalling an end of the shaft thereon, and

a vortex separator connected to said outlet means to receive part of the pumped material, and means connecting to the vortex separator for flow of its clear liquid output to said chamber adjacent said wear ring for flushing the said wear ring.

2. A centrifugal pump and motor as in claim 1 where said impeller includes front and rear face shroud means, the flushing liquid flowing outwardly between the rear impeller shroud means and a chamber wall provided on the impeller and housing means, respectively, the impeller having at least one substantially axially directed hole extending therethrough radially offset from the impeller axis to conduct seal flushing liquid to a clearance space provided between the front impeller shroud means and the chamber wall.

3. A centrifugal pump and motor as in claim 1 and including a closed chamber forming means around said shaft between the pump and the motor, a pair of axially spaced seal means engaging said shaft at opposed ends of the chamber, and a fixed volume of liquid seal lubricant received and substantially filling the closed chamber.

4. A centrifugal pump and motor as in claim 1 where the motor has an insulating liquid enclosed therein, a pair of bearings engage the motor shaft, and liquid circulation means are formed in the shaft and extend the length of the motor for circulation of such liquid through said bearings.

5. A self contained centrifugal pump and motor unit comprising an impeller and housing means therefor forming a pump chamber and a pump including an axial diffuser, a motor in axial alignment with said impeller, a common shaft for the motor rotor and the impeller, a tubular means encompassing said motor for the length thereof and connecting to said axial diffuser for flow of pumped liquid therethrough for cooling the motor, an outlet means connecting to said tubular means, means on said outlet means journalling an end of the shaft thereon, means sealing said motor in the pump and motor unit, and characterized by a vortex separator connected to said outlet means to receive part of the pumped material, means connected to said vortex separtor to receive clear liquid output therefrom, which means connect to a rear wall of the pump chamber for supply of clear liquid to the pump chamber to flush the clearance space provided for the impeller in the pump chamber.

6. A self contained centrifugal pump and motor unit as in claim 5 where the motor has a lubricating liquid enclosed in its rotor and in its stator, a pair of bearings engage the motor shaft at axially opposed ends of the motor, and liquid circulation means are formed in the shaft and extend the length of the motor for circulation of said liquid through the motor and said bearings, the bearings and motor being within a common enclosure.

7. A self contained centrifugal pump and motor unit as in claim where said impeller has front and rear face shroud means, and said impeller has a hub engaging said shaft and said impeller and hub have at least one substantially axially directed bore means extending through the impeller and its said shroud means to conduct part of the flushing liquid to a clearance space provided between the front impeller shroud means and the chamber wall for radial outward flow of the flushing liquid along both of said shroud means.

8. In a centrifugal pump and motor unit comprising an impeller and housing means therefor forming an impeller chamber adapted to pump water containing abrasive means and an inlet in a front wall of the impeller chamber, said housing means including a back wear ring on the back wall of the impeller chamber, a motor in axial alignment with said impeller, and characterized a seal means engaging said shaft spaced from said impeller chamber but operatively connecting thereto, and

means connecting to said unit to supply flushing liquid to said chamber adjacent said wear ring and seal means for flushing the same.

9. in a centrifugal pump and motor unit as in claim 8 where said impeller includes front and rear face shroud means, the flushing liquid flowing to an enclosure formed around said shaft and connecting to the impeller chamber at the back wall thereof and for flow outwardly between the rear impeller shroud means and the chamber back wall.

10. In a centrifugal pump and motor unit as in claim 9 where said impeller has a hub engaging said shaft and said impeller and hub have at least one substantially axially directed bore means extending the axial length of the impeller axis to conduct flushing liquid to a clearance space provided between the front impeller shroud means and the chamber wall and offset from the chamber inlet. 

1. A centrifugal pump and motor comprising an impeller and housing means therefor forming an impeller chamber adapted to pump water containing abrasive means, said housing means including a back wear ring, an axial diffuser, a motor in axial alignment with said impeller, a common shaft for the motor rotor and the impeller, tubular means encompassing said motor for the length thereof and connecting to said axial diffuser for flow of pumped liquid therethrough for cooling the motor, an outlet means connecting to said tubular means, means on said outlet means journalling an end of the shaft thereon, and a vortex separator connected to said outlet means to receive part of the pumped material, and means connecting to the vortex separator for flow of its clear liquid output to said chamber adjacent said wear ring for flushing the said wear ring.
 2. A centrifugal pump and motor as in claim 1 where said impeller includes front and rear face shroud means, the flushing liquid flowing outwardly between the rear impeller shroud means and a chamber wall provided on the impeller and housing means, respectively, the impeller having at least one substantially axially directed hole extending therethrough radially offset from the impeller axis to conduct seal flushing liquid to a clearance space provided between the front impeller shroud means and the chamber wall.
 3. A centrifugal pump and motor as in claim 1 and including a closed chamber forming means around said shaft between the pump and the motor, a pair of axially spaced seal means engaging said shaft at opposed ends of the chamber, and a fixed volume of liquid seal lubricant received and substantially filling the closed chamber.
 4. A centrifugal pump and motor as in claim 1 where the motor has an insulating liquid enclosed therein, a pair of bearings engage the motor shaft, and liquid circulation means are formed in the shaft And extend the length of the motor for circulation of such liquid through said bearings.
 5. A self contained centrifugal pump and motor unit comprising an impeller and housing means therefor forming a pump chamber and a pump including an axial diffuser, a motor in axial alignment with said impeller, a common shaft for the motor rotor and the impeller, a tubular means encompassing said motor for the length thereof and connecting to said axial diffuser for flow of pumped liquid therethrough for cooling the motor, an outlet means connecting to said tubular means, means on said outlet means journalling an end of the shaft thereon, means sealing said motor in the pump and motor unit, and characterized by a vortex separator connected to said outlet means to receive part of the pumped material, means connected to said vortex separtor to receive clear liquid output therefrom, which means connect to a rear wall of the pump chamber for supply of clear liquid to the pump chamber to flush the clearance space provided for the impeller in the pump chamber.
 6. A self contained centrifugal pump and motor unit as in claim 5 where the motor has a lubricating liquid enclosed in its rotor and in its stator, a pair of bearings engage the motor shaft at axially opposed ends of the motor, and liquid circulation means are formed in the shaft and extend the length of the motor for circulation of said liquid through the motor and said bearings, the bearings and motor being within a common enclosure.
 7. A self contained centrifugal pump and motor unit as in claim 5 where said impeller has front and rear face shroud means, and said impeller has a hub engaging said shaft and said impeller and hub have at least one substantially axially directed bore means extending through the impeller and its said shroud means to conduct part of the flushing liquid to a clearance space provided between the front impeller shroud means and the chamber wall for radial outward flow of the flushing liquid along both of said shroud means.
 8. In a centrifugal pump and motor unit comprising an impeller and housing means therefor forming an impeller chamber adapted to pump water containing abrasive means and an inlet in a front wall of the impeller chamber, said housing means including a back wear ring on the back wall of the impeller chamber, a motor in axial alignment with said impeller, and characterized by a seal means engaging said shaft spaced from said impeller chamber but operatively connecting thereto, and means connecting to said unit to supply flushing liquid to said chamber adjacent said wear ring and seal means for flushing the same.
 9. In a centrifugal pump and motor unit as in claim 8 where said impeller includes front and rear face shroud means, the flushing liquid flowing to an enclosure formed around said shaft and connecting to the impeller chamber at the back wall thereof and for flow outwardly between the rear impeller shroud means and the chamber back wall.
 10. In a centrifugal pump and motor unit as in claim 9 where said impeller has a hub engaging said shaft and said impeller and hub have at least one substantially axially directed bore means extending the axial length of the impeller axis to conduct flushing liquid to a clearance space provided between the front impeller shroud means and the chamber wall and offset from the chamber inlet. 